A forklift driver is "very, very lucky" to be alive after a 12 metre shipping container fell onto the cab of his forklift.

Fire officer Gary Tomlins said his team had horrible thoughts when they received a call about a man trapped under a shipping container in a storage facility in the south Auckland suburb of Mangere.

But when they arrived they found the man was fine.

He had already been freed - the cage of his forklift cab having withstood the massive load.

"We informed the driver he should go and buy a lotto ticket immediately," Mr Tomlins.

It appeared the forklift had been lifting two shipping containers when the top one clipped another stack of containers and crashed onto the forklift.

Cranes would have to be brought in to rearrange the containers which were in chaos, Mr Tomlins said.